Despite its innovations, the XP-31 did not offer any advantages compared to its rival the Boeing P-26 Peashooter and was not ordered into series production.

It was the AAC's first single-seat closed-cockpit fighter, and the last with fixed gear and wing struts.

Despite its small size, it was badly overweight, and carried 125 gallons (104 imp gal, 474 L) of fuel.

Although Curtiss considered the design significant in that it introduced various new technologies, compared to its contemporaries the XP-31 was already outmoded, and, more importantly, testing showed that it fell below performance expectations.

[2] Powered by a 700 hp (520 kW) R-1750 Cyclone radial, its performance was dismal, despite retractable leading edge slots and large trailing-edge flaps, so a 600 hp (450 kW) Curtiss V-1570 Conqueror was substituted.